To solve problems possessed by conventional methods for the purpose of making it easy to uniformly mix grain flour and the butter, when a grain preparation which uses the grain flour, such as wheat flour, conventionally used as a food-producing raw material and the butter as main raw materials is produced, such as a method for using butter by softening the butter at a room temperature, a method for using the butter by heating and fluidizing the butter, a method for using the soft butter which is in a state of being immediately after discharged from a butter production machine and of which the crystals are not stabilized, or the like.

In this method for producing the grain flour preparation which uses the grain flour and the butter as the main raw materials, the butter which exhibits a solid state at a low temperature is softened in a room equipped with air circulation-type room temperature regulation equipment having heating and cooling functions. Thus, the butter is softened within one week, without being affected by the season, and therefore the butter which keeps a fresh state and the grain flour are easily and uniformly mixed.